Identification and significance of a visible, basalt-rich Vedde Ash layer in a Late-glacial sequence on the Isle of Skye, Inner Hebrides, Scotland

This paper reports the discovery of a visible, tephra horizon of Late-glaci al age from the site of Loch Ashik in the Isle of Skye, the Inner Hebrides, Scotland. Although the tephra shards have a bimodal geochemical compositio n identical to that of the Vedde Ash a well known marker horizon within Lat e-glacial sequences. The horizon at Ashik is dominated by basaltic shards a nd devitrified tephra shards, giving the layer its characteristic black col our. Only rhyolitic shards have previously been reported from Vedde Ash hor izons in the British Isles. This new evidence raises some important questio ns about the factors that govern the distribution and accumulation of basal tic tephra, and about the methods used to detect ash shards in basins dista l to centres of volcanic activity. Copyright (C) 2001 John Wiley & Sons, Lt d.